Process for producing highly pure chlorinated alkane

ABSTRACT

Disclosed is a process for producing highly pure chlorinated alkane in which a chlorinated alkene is contacted with chlorine in a reaction zone to produce a reaction mixture containing the chlorinated alkane and the chlorinated alkene, and extracting a portion of the reaction mixture from the reaction zone, wherein the molar ratio of chlorinated alkane:chlorinated alkene in the reaction mixture extracted from the reaction zone does not exceed 95:5.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 16/355,851,filed Mar. 18, 2019, which is a continuation of U.S. application Ser.No. 15/708,159, filed Sep. 19, 2017, now U.S. Pat. No. 10,479,744, whichis a continuation of U.S. application Ser. No. 14/883,646, filed Oct.15, 2015, now U.S. Pat. No. 9,790,148, which claims priority of CzechPatent Application No. PV 2014-705, filed Oct. 16, 2014, each of whichare hereby incorporated by reference in their entirety.

The present invention relates to processes for producing very highpurity chlorinated alkane compounds, such as1,1,1,2,3-pentachloropropane, 1,1,2,2,3-pentachloropropane,1,1,1,3,3-pentachloropropane, 1,1,1,2,3,3-hexachloropropane,1,1,1,2,3,3,3-heptachloropropane, 1,1,1,2,2,3,3-heptachloropropane and1,1,1,2,2,3,3,3-octachloropropane and 1,1,1,2,4,4,4-heptachlorobutaneand also to compositions comprising such compounds.

Haloalkanes find utility in a range of applications. For example,halocarbons are used extensively as refrigerants, blowing agents andfoaming agents. Throughout the second half of the twentieth century, theuse of chlorofluoroalkanes increased exponentially until the 1980's,when concerns were raised about their environmental impact, specificallyregarding depletion of the ozone layer.

Subsequently, fluorinated hydrocarbons such as perfluorocarbons andhydrofluorocarbons have been used in place of chlorofluoroalkanes,although more recently, environmental concerns about the use of thatclass of compounds have been raised and legislation has been enacted inthe EU and elsewhere to reduce their use.

New classes of environmentally friendly halocarbons are emerging andhave been investigated, and in some cases, embraced in a number ofapplications, especially as refrigerants in the automotive and domesticfields. Examples of such compounds include 1,1,1,2-tetrafluoroethane(R-134a), 2-chloro-3,3,3-trifluoropropene (HFO-1233xf),1,3,3,3-tetrafluoropropene (HFO-1234ze), 3,3,3-trifluoropropene(HFO-1243zf), and 2,3,3,3-tetrafluoropropene (HFO-1234yf),1,2,3,3,3-pentafluoropropene (HFO-1225ye),1-chloro-3,3,3-trifluoropropene (HFO-1233zd),3,3,4,4,4-pentafluorobutene (HFO-1345zf), 1,1,1,4,4,4-hexafluorobutene(HFO-1336mzz), 3,3,4,4,5,5,5-heptafluoropentene (HFO1447fz),2,4,4,4-tetrafluorobut-1-ene (HFO1354mfy) and1,1,1,4,4,5,5,5-octafluoropentene (HFO-1438mzz)

While these compounds are, relatively speaking, chemically non-complex,their synthesis on an industrial scale to the required levels of purityis challenging. Many synthetic routes proposed for such compoundsincreasingly use, as starting materials or intermediates, chlorinatedalkanes or alkenes. Examples of such processes are disclosed inWO2012/098420, WO2013/015068 and US2014/171698. The conversion of thechlorinated alkane or alkene starting materials to the fluorinatedtarget compounds is usually achieved using hydrogen fluoride andoptionally transition metal catalysts, for example chromium-basedcatalysts.

An example of an optionally non-catalytic process for preparingfluoroalkenes is disclosed in WO2013/074324.

The issue of the formation of impurities during hydrofluorinationreactions is considered in US2010/331583 and WO2013/119919, where thusthe need for part fluorinated feedstock purity is described, and also inUS2014/235903 regarding reactor impurities.

It has been recognised that when the chlorinated feedstock is obtainedfrom a multi-step process, especially if such steps are linked and runcontinuously to achieve industrially acceptable product volumes, thenthe need to prevent cumulative side reactions from generatingunacceptable impurities at each process step is very important.

The purity of the chlorinated starting materials will have a substantialeffect on the success and viability of the processes (especiallycontinuous processes) for preparing the desirable fluorinated products.The presence of certain impurities will result in side reactions,minimising the yield of the target compound. Removal of these impuritiesthrough the use of distillation steps is also challenging. Additionally,the presence of certain impurities will compromise catalyst life, by,for example, acting as catalyst poisons.

Accordingly, there is a need for high purity chlorinated alkanes for usein the synthesis of the fluorinated compounds mentioned above. Severalprocesses for producing purified chlorinated compounds have beenproposed in the art.

For example, WO2013/086262 discloses a process for preparing1,1,2,2,3-pentachloropropane from methylacetylene gas. As can be seenfrom the examples in that application, the bench scale synthesesdisclosed therein resulted in a product having around 98.5% purity,despite being subjected to post-synthetic purification process steps,specifically distillation.

In WO2014/130445, a conventional process is discussed on page 2 of thatpublication, the first step of which involves the formation of1,1,1,2,3-pentachloropropane from 1,1,3-trichloropropene. However, thepurity profile of that intermediate product is not outlined, nor is anyimportance attached to the purity profile of that product. In Example 2of WO2014/130445, a 240 db (1,1,1,2,3-pentachloropropane) rich materialhaving a purity level of 96.5 to 98.5% is used.

WO2013/055894 discloses a process for producing tetrachloropropenes,particularly 1,1,2,3-tetrachloropropene and reports that the productobtained from the processes disclosed in that document haveadvantageously low levels of impurities which can be problematic indownstream processes for producing fluorocarbons. A discussion of thedifferent types of impurities considered to be problematic by theauthors of WO2013/055894 is set out in paragraphs [0016] and [0017] ofthat document

US2012/157723 discloses a process in for preparing chlorinated alkanesvia a three step process. Seemingly high purity chloroalkanes appear tohave been prepared according to the process disclosed in that document.However, the purity data presented in the examples of that applicationare only given to one decimal place.

From the provision of data presented in this way, it is apparent thatthe analytical equipment used to measure the impurity profile of theproducts obtained in the examples of US2012/157723 was insensitive;conventional analytical apparatus enables hydrocarbon levels to 1 ppm(i.e. to four decimal places). Given that one skilled in the art wouldneed to know the impurity profile of chloroalkane feedstocks to be usedin industrial scale down to a ppm level, the data presented inUS2012/157723 would not be of assistance.

The skilled person would also recognise that the process disclosed inUS2012/157723 provides 1,1,1,2,3-pentachloropropane which has relativelylow selectivity; as can be seen, from paragraph [0146] of that document,selectivity towards the compound of interest was 95%.

Additional processes in which processes are streamlined by using crudeintermediates in downstream stages are disclosed in WO2009/085862.

Despite these advances, problems can still arise through the use ofchlorinated compounds obtained from the processes discussed above.Particularly, the presence of impurities especially those which are noteasily separable from the compounds of interest (e.g. as a result ofsimilar or higher boiling points) or which reduce the effectiveness oroperating life of catalysts used in downstream processes can beproblematic.

To minimise such drawbacks, a demand remains for very high puritychlorinated alkane compounds, and also for efficient, selective andreliable processes for preparing such compounds, especially enablingcontinuous industrial manufacture.

Thus, according to a first aspect of the present invention, there isprovided a process for producing highly pure chlorinated alkane in whicha chlorinated alkene is contacted with chlorine in a reaction zone toproduce a reaction mixture containing the chlorinated alkene and thechlorinated alkane and extracting a portion of the reaction mixture fromthe reaction zone, wherein the molar ratio of chlorinatedalkane:chlorinated alkene in the reaction mixture extracted from thereaction zone does not exceed 95:5.

The molar ratio of chlorinated alkane:chlorinated alkene in the reactionmixture is controlled within numerically defined limits. As thoseskilled in the art will appreciate, in such embodiments, while controlover the process is characterised herein in terms of the molar ratiobetween the chlorinated alkane starting material and the chlorinatedalkene product, it can also considered as control over the conversion ofstarting material to product—thus a molar ratio of chlorinatedalkane:chlorinated alkene of 95:5 equates to a conversion of 95%. Theinventors have found that limiting the conversion of the startingmaterial as outlined above minimises the formation of undesirableimpurities. Additionally, where reference is made to a molar ratio ofthe starting material:product being greater than a given value, thismeans a greater degree of conversion of the starting material toproduct, i.e. such that the proportion of the product is increased whilethe proportion of the starting material is decreased.

In embodiments of the invention, the reaction zone may be a primaryreaction zone.

The processes of the present invention involve the chlorination of analready chlorinated alkene to convert to the chlorinated alkane compoundof interest. The process is highly selective.

One of the advantages of the processes of the present invention is thatthey permit the production of a target chlorinated alkane with highisomeric selectivity. Thus, in embodiments of the invention, thechlorinated alkane product is produced with isomeric selectivity of atleast about 95%, at least about 97%, at least about 98%, at least about99%, at least about 99.5%, at least about 99.7%, at least about 99.8% orat least about 99.9%.

It has been found that such highly pure chlorinated alkane materials areless susceptible to degradation during storage and transport. It isbelieved that this is due to the absence (or presence in only traceamounts) of impurities which would otherwise trigger decomposition ofthe chlorinated alkane of interest. Accordingly, the use of stabilisingagents can advantageously be avoided.

A further advantage of the processes of the present invention is that,through control of the degree of conversion of the starting material tofinished product, the formation of otherwise problematic serial productsis minimised. Accordingly, in embodiments of the invention, reactionmixture extracted from the primary reaction zone, and/or chlorinatedalkane rich material extracted from the principal reaction zone,comprises low levels of serial reaction products, i.e. compoundscomprising a greater number of chlorine and/or carbon atoms than thechlorinated alkane product, for example in amounts of less than about5%, less than about 2%, less than about 1%), less than about 0.5%, lessthan about 0.2%, less than about 0.1%, less than about 0.05% or lessthan about 0.02%.

In embodiments of the invention, the process may be continuous.

It has unexpectedly been found that through the careful control of thelevel of chlorinated alkane in the reaction mixture formed in theprimary reaction zone, the production of impurities is minimised, and/orhigh selectivity for the desired chlorinated alkane, is achieved. Thelevel of chlorinated alkane in the reaction mixture may be controlledby, for example, i) removing the chlorinated alkane (eitherspecifically, or by extracting reaction mixture) from the primaryreaction zone/s, ii) by controlling the reaction conditions in theprimary reaction zone (e.g. temperature, exposure to light, and/orpressure), and/or iii) by controlling the amount of chlorinated alkeneand/or chlorine present in the primary reaction zone.

For example, the amount of chlorine present in the reaction mixture canbe controlled such that there is no molar excess of chlorine present inthe reaction mixture in the primary and/or principal reaction zone/s

Any conditions which result in the formation of the chlorinated alkanemay be employed in the primary reaction zone. However, in embodiments ofthe invention, the operating temperature in the primary reaction zone ismaintained at a relatively low level, for example about 100° C. orlower, about 90° C. or lower or about 80° C. or lower. The operatingtemperature of the primary reaction zone may be about −30° C., about−20° C., about −10° C. or about 0° C. to about 20° C., about 40° C., orabout 75° C. The use of such temperatures in the primary reaction zonehas been found unexpectedly to be advantageous as this results in areduction in the formation of isomers of the target chlorinated alkaneand over-chlorinated compounds, yet gives the required productselectively in high yield. To increase the reaction rate at thesetemperatures, light (visible and/or ultra violet) may optionally be usedto promote the addition of chlorine at these low temperatures.

The operating temperature in the primary reaction zone may be controlledby any temperature control means known to those skilled in the art, forexample heating/cooling jackets, heating/cooling loops either internalor external to the reactor, heat exchangers and the like. Additionallyor alternatively, the temperature may be controlled by controlling thetemperature of material/s added into the reaction mixture, thus,controlling the temperature of the reaction mixture. The reactionmixture is maintained in the primary reaction zone for a time and underconditions sufficient to achieve the required level of chlorinatedalkane in the reaction mixture.

In embodiments of the invention, the primary reaction zone may beexposed to light, for example visible light and/or ultra violet light.Exposure of the reaction mixture to light promotes the reaction whenoperated at low temperatures which is advantageous where the use ofhigher temperatures is to be avoided.

For the avoidance of doubt, in embodiments of the invention, the primaryconversion step may be carried out in a plurality of primary reactionzones (e.g. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more primary reactionzones), which may be operated at the same or different pressures,temperatures and/or light conditions.

In embodiments of the present invention, the residence time of thereaction mixture in the primary reaction zone may range from about 30 to300 minutes, from about 40 to about 120 minutes or from about 60 toabout 90 minutes.

Optimal results have been observed when the level of chlorinated alkanein the reaction mixture present in the primary reaction zone ismaintained at a level such that the molar ratio of chlorinatedalkane:chlorinated alkene in reaction mixture extracted from the primaryreaction zone does not exceed 50:50. In embodiments of the invention,the level of chlorinated alkane present in the reaction mixture in theprimary reaction zone may be maintained at lower levels, for examplesuch that the molar ratio of chlorinated alkane:chlorinated alkene inreaction mixture extracted from the primary reaction zone does notexceed 75:25, 50:50, 40:60 or 30:70. Additionally or alternatively, thelevel of chlorinated alkane in the reaction mixture present in theprimary reaction zone/s is maintained at a level such that the molarratio of chlorinated alkane:chlorinated alkene in reaction mixtureextracted from the primary reaction zone is at least 5:95, 10:90, 15:85,20:80, 30:70, 40:60 or 50:50.

The composition of reaction mixture, enabling a determination of themolar ratio of chlorinated alkane:chlorinated alkene, may be determinedas soon as is practicable following extraction of the reaction mixturefrom the primary reaction zone. For example, a sample of reactionmixture may be extracted at a point adjacent to or slightly downstreamof the outlet of the primary reaction zone. In embodiments of theinvention, the outlet may be located at the upper end of the primaryreaction zone.

Reaction mixture comprising chlorinated alkene starting material andchlorinated alkane product may be extracted from the primary and/orprincipal reaction zone either continuously or intermittently. Oneskilled in the art would recognise that, in embodiments where reactionmixture/chloroalkane rich product is extracted from the respectivereaction zone, that material may be removed on a substantiallycontinuous basis while the zone in question is at operating conditionsand, if its purpose is to set up a steady state reaction (e.g. anchlorination), once the reaction mixture therein has attained therequired steady state.

In embodiments of the present invention, the reaction conducted in theprimary reaction zone is in the liquid phase, i.e., the reaction mixturepresent therein is predominantly or totally liquid. The reaction mixturemay be analysed using any techniques known to those skilled in the arte.g. chromatography.

The chlorinated alkene employed in the processes of the presentinvention may be fed into the primary reaction zone using any techniqueknown to those skilled in the art. The chlorinated alkene may be a C₂₋₆chloroalkene, for example, chloroethene, chloropropene or chlorobutene,or a C₃₋₆ chloroalkene. Examples of chlorinated alkenes which may beemployed in the processes of the present invention include1,1,3-trichloropropene, 1,1,2-trichloropropene, 2,3,3-trichloropropene,1,1,4,4,4-pentachlorobutene, 3,3,3-trichloropropene,1,2,3-trichloropropene, 1,3-dichloropropene, 2-chloropropene,1,1-dichloropropene, 1,1,2,3-tetrachloropropene,1,1,3,3-tetrachloropropene, 1,1,2,3,3-pentachloropropene,1,1,3,3,3-pentachloropropene and 1,1,2,3,3,3-hexachloropropene.

Chlorinated butenes, pentenes or hexenes may be employed in theprocesses of the present invention to produce chlorinated C₄₋₆ compoundswhich find utility in the production of fluorinated compounds having lowglobal warming potential.

The chlorinated alkene used as a starting material in the processes ofthe present invention preferably has a high degree of purity. Inembodiments of the invention, the chlorinated alkene has a purity levelof at least about 95%, at least about 97%, at least about 99%, or atleast about 99.5%.

Additionally or alternatively, the chlorinated alkene may include lessthan about 2%, less than about 1%, less than about 0.1%, less than about0.01% or less than about 0.001% by weight of chlorinated alkene and/orchlorinated alkane impurities. For example, where the chlorinated alkenestarting material is 1,1,3-trichloropropene, the 1,1,3-trichloropropenestarting material may comprise less than about 2%, less than about 1%,less than about 0.1%, less than about 0.01% or less than about 0.001% byweight of chlorinated alkene impurities such as perchlorethylene,tetrachloroethylene, hexachloroethylene and/or chlorinated alkaneimpurities such as 1,1,1,3-tetrachloropropane.

Processes for producing high purity chlorinated alkene are disclosed inUK Patent Application No. 1418345.3 and Czech Patent Application No. PV2014-706, the contents of which are incorporated herein by reference.Products of those processes may advantageously comprise:

about 95% or more, about 97% or more, about 99% or more, about 99.2% ormore about 99.5% or more or about 99.7% or more of the chlorinatedalkene, less than about 1000 ppm, less than about 500 ppm, less thanabout 200 ppm, or less than about 100 ppm of chlorinated C₅₋₆ alkaneimpurities, less than about 1000 ppm, less than about 500 ppm, less thanabout 200 ppm, or less than about 100 ppm of chlorinated alkeneimpurities (i.e. chlorinated alkenes other than the starting material),less than about 500 ppm, less than about 200 ppm, less than about 100ppm, less than about 50 ppm, less than about 20 ppm, less than about 10ppm or less than about 5 ppm metal (e.g. iron), less than about 1000ppm, less than about 500 ppm, less than about 250 ppm, or less thanabout 100 ppm of oxygenated organic compounds, and/or less than about500 ppm, about 250 ppm or less, about 100 ppm or less or about 50 ppm orless of water.

For the avoidance, the limits of metal outlined above encompass metal inelemental form (e.g. particulate metal) as well as in ionic form (e.g.in the form of a salt).

The chlorinated alkene material used as a starting material in theprocesses of the present invention may be provided in a compositionhaving the impurity profile as outlined above.

The chlorinated alkane produced in the processes of the invention may bea C₂₋₆ chloroalkane, for example, chloroethane, chloropropane orchlorobutane, or a C₃₋₆ chloroalkane. Examples of chlorinated alkaneswhich may be produced in the processes of the invention include1,1,1,2,3-pentachloropropane, 1,1,2,3-tetrachloropropane,1,1,2,2,3-pentachloropropane, 1,1,1,2,2-pentachloropropane,1,1,1,2,4,4,4-heptachlorobutane, 1,1,1,2,3,3-hexachloropropane,1,1,1,2,3,3,3-heptachloropropane, 1,1,1,2,2,3,3-heptachloropropane and1,1,1,2,2,3,3,3-octachloropropane.

The feed of chlorine and/or chlorinated alkene into the primary reactionzone/s and/or principal reaction zone/s employed in processes of thepresent invention may be continuous or intermittent.

Chlorine may be fed into reaction zone/s employed in the processes ofthe present invention in liquid and/or gaseous form, either continuouslyor intermittently. For example, the primary reaction zone may be fedwith one or more chlorine feeds. Additionally or alternatively, reactionzone/s downstream of the primary reaction zone (e.g. the principalconversion zone) may be fed with one or more chlorine feeds. Inembodiments of the invention, the only reaction zone supplied withchlorine is the primary reaction zone.

Where the reaction mixture in the reaction zone/s is liquid, thechlorine may be fed into the reaction zone/s as gas and dissolved in thereaction zone. In embodiments, the chlorine is fed into reaction zone/svia dispersing devices, for example, nozzles, porous plates, tubes,ejectors, etc. The chlorine, in embodiments of the invention, may be feddirectly into the liquid reaction mixture. Additionally oralternatively, the chlorine may be fed into liquid feeds of otherreactants upstream of the reaction zone/s.

Additional vigorous stirring may be used to ensure good mixing and/ordissolution of the chlorine into the liquid reaction mixture.

The chlorine used as a starting material in the processes of the presentinvention is preferably highly pure. In embodiments of the invention,the chlorine fed into the reaction zone/s employed at any stage in thepresent invention preferably has a purity of at least about 95%, atleast about 97%, at least about 99%, at least about 99.5%, or at leastabout 99.9%

Additionally or alternatively, the chlorine used in the processes of thepresent invention may comprise bromine or bromide in an amount of about200 ppm or less, about 100 ppm or less, about 50 ppm or less, about 20ppm or less or about 10 ppm or less.

The use of chlorine gas comprising low amounts of oxygen (e.g. about 200ppm or less, about 100 ppm or less, about 50 ppm or less, about 20 ppmor less or about 10 ppm or less) is also envisaged. However, inembodiments of the present invention, lower grade chlorine (includinghigher oxygen levels, e.g. of 1000 ppm or higher) can advantageously beemployed without the final product of the processes of the presentinvention comprising unacceptably high levels of oxygenated impurities.

As mentioned above, it is envisaged that in embodiments of theinvention, the reaction mixture present in the primary reaction zonewill be liquid. However, alternative embodiments are envisaged in whichthe reaction mixture is gaseous. In such embodiments, the primaryreaction zone may be operated at temperatures of about 150° C. to about200° C. Gas phase reactors, for example, one or more tubular gas phasereactors, may be employed in such embodiments.

The term ‘highly pure’ as used herein means about 95% or higher purity,about 99.5% or higher purity, about 99.7% purity, about 99.8% or higherpurity, about 99.9% or higher purity, or about 99.95% or higher purity.Unless otherwise specified, values presented herein as percentages areby weight.

Extraction of the reaction mixture from the primary reaction zone can beachieved using any technique known to those skilled in the art.Typically, reaction mixture extracted from the primary reaction zonewill comprise unreacted chlorinated alkene, unreacted chlorine andchlorinated alkane. Alternatively, where control of the formation ofchlorinated alkane is achieved by controlling (i.e. limiting) the amountof chlorine fed into the primary reaction zone, the reaction mixtureextracted from the primary reaction zone may comprise very low levels ofchlorine, for example about 1% or less, about 0.5% or less, about 0.1%or less, about 0.05% or less or about 0.01% or less.

In embodiments of the invention, where reaction mixture comprisingunreacted chlorinated alkene is extracted from the primary reactionzone, a principal conversion step may be performed in which majoritysignificant proportion, but not all, of the unreacted chlorinated alkenepresent in the reaction mixture extracted from the primary reaction zoneis converted to chlorinated alkane, thus producing a chlorinated alkanerich product, which is then extracted from the principal reaction zone.The chlorinated alkane rich product may comprise unreacted chlorinatedalkene starting material and chlorinated alkane product.

In such embodiments, the reaction mixture may additionally comprisechlorine. Additionally or alternatively, chlorine may be fed into theprincipal reaction zone to enable the chlorination reaction to proceed.

The degree of conversion of the chlorinated alkene to chlorinated alkaneis controlled such that the molar ratio of chlorinatedalkane:chlorinated alkene present in the chlorinated alkane rich productextracted from the principal reaction zone does not exceed about 95:5,about 93:7, about 91:9, about 90:10 or about 87.5:12.5.

Additionally or alternatively, the degree of conversion of thechlorinated alkene to chlorinated alkane is controlled such that themolar ratio of chlorinated alkane:chlorinated alkene present in thechlorinated alkane rich product extracted from the principal reactionzone is greater than about 70:30, about 75:25, about 80:20 or about85:15.

In certain embodiments of the present invention in which a principalreaction step is carried out, the molar ratio of chlorinatedalkane:chlorinated alkene present in the chlorinated alkane rich productextracted from the principal reaction zone is greater than that forreaction mixture extracted from the primary reaction zone. In otherwords, the degree of conversion of the starting material to product ishigher for the product extracted from the principal reaction zone thanfor the reaction mixture extracted from the primary reaction zone.

In embodiments of the invention in which a chlorinated alkane richproduct is employed or produced, it may have the chlorinatedalkane:chlorinated alkene ratios outlined above.

It has unexpectedly been found that through the careful control of thedegree of conversion of the chlorinated alkene in the principal reactionzone, the production of impurities is minimised. The level ofchlorinated alkane in the reaction mixture may be controlled by, forexample, i) removing the chlorinated alkane (either specifically, or byextracting chlorinated alkane rich product) from the principal reactionzone, ii) by controlling the reaction conditions in the principalreaction zone (e.g. temperature, exposure to light, and/or pressure),and/or iii) by controlling the amount of chlorinated alkene and/orchlorine present in the principal reaction zone.

In embodiments of the invention in which the degree of conversion of thechlorinated alkene to the chlorinated alkane is controlled (i.e.limited) by controlling the amount of chlorine present in the principalreaction zone (e.g. supplied directly thereto and/or present as acomponent of the reaction mixture), the chlorine content in the obtainedchlorinated alkane rich product may be very low, for example about 1% orless, about 0.5% or less, about 0.1% or less, about 0.05% or less orabout 0.01% or less.

This principal conversion step will typically take place in one or moreprincipal reaction zones downstream of the primary reaction zone. Anynumber of principal reaction zones may be employed in the processes ofthe present invention, for example 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or moreprincipal reaction zones.

Any conditions which result in the conversion of chlorinated alkene tochlorinated alkane may be employed in the principal conversion step. Inembodiments of the invention, the principal conversion step may comprisea reduced temperature conversion step. When such a step is performed,the reduction in temperature of the extracted reaction mixture ispreferably achieved by feeding the reaction mixture into a principalreaction zone operated at a reduced temperature (for example about −30to about 30° C., about −25 to about 10° C., or more preferably about −20to about −10° C.) and extracting a chlorinated alkane rich product fromthe principal conversion zone.

It has been unexpectedly found that maintaining, at low temperature, areaction mixture comprising chlorinated alkene, chlorine and chlorinatedalkane, results in the conversion of chlorinated alkene to chlorinatedalkane while minimising the production of unwanted impurities, improvingselectivity and/or the yield.

Thus, according to a further aspect of the invention, there is provideda process for producing highly pure chlorinated alkane comprising areduced temperature conversion step in which a reaction mixturecomprising chlorinated alkene, and chlorinated alkane is fed into aprincipal reaction zone, operated at a temperature of about −30° C. toabout 30° C., about −25° C. to about 10° C., or more preferably about−20° C. to about −10° C., and extracting a chlorinated alkane richproduct from the principal reaction zone.

For certain embodiments, exposure of the reaction mixture in theprincipal reaction zone to light (for example ultra violet light) isuseful in conducting the reaction successfully at low temperatures.

In aspects of the invention, the ratio of chlorinated alkane:chlorinatedalkene present in the reaction mixture fed in to the principal reactionzone may be 70:30 or lower, 60:40 or lower, 50:50 or lower, 40:60 orlower or 30:70 or lower and/or 5:95 or higher, 10:90 or higher, 20:80 orhigher or 40:60 or higher.

In embodiments of the invention, the operating temperature of theprincipal reaction zone may be achieved in a single cooling action, or aseries of cooling actions in which the principal reaction zone/s areoperated at successively lower temperatures. Operating the principalreaction zone/s at reduced temperature can be achieved using anytechnique known to those skilled in the art.

The reduced temperature conversion step preferably takes place in one ormore principal reaction zones downstream of the primary reaction zone.For example, where the reduced temperature conversion step requires asingle cooling action, it may occur in a single principal reaction zone.Where the reduced temperature conversion step requires a series ofcooling actions, this may be achieved in a single principal reactionzone, or in a plurality of principal reaction zones.

In embodiments of the present invention, the reaction mixture ismaintained in the principal reaction zone for a time and underconditions sufficient to achieve the required level of chlorinatedalkane in the reaction mixture.

The principal reaction zone/s may be operated under subatmospheric,atmospheric or superatmospheric pressure.

Additionally or alternatively, the primary and/or the principal reactionzone/s may be exposed to light, for example visible light and/or ultraviolet light.

In embodiments of the present invention, the residence time of thereaction mixture in the principal reaction zone may range from about 30to 300 minutes, from about 40 to about 120 minutes or from about 60 toabout 90 minutes.

In embodiments of the present invention, the reaction conducted in theprincipal reaction zone is in the liquid phase, i.e, the reactionmixture present therein is predominantly or totally liquid.

In embodiments of the invention, reaction mixture extracted from theprimary reaction zone is subjected directly to the principal conversionstep. In alternative embodiments, the extracted reaction mixture issubjected to one or more pre-treatment steps prior to being subjected tothe principal conversion step.

In embodiments of the invention, to attain the desired level ofchlorinated alkane in the chlorinated alkane rich product, the principalconversion step may involve heating the chlorinated alkane rich productto elevated temperatures, for example to about 20° C. or higher, about30° C. or higher, about 40° C. or higher, about 50° C. or higher orabout 60° C. or higher.

Heating the chlorinated alkane rich product in this way may be achievedin a single heating step. Alternatively, the chlorinated alkane richproduct may be subjected to a series of heating steps at successivelyhigher temperatures.

As mentioned above, different reaction zones may be operated atdifferent temperatures, pressure and/or to the exposure to differingtypes and/or intensity of light. For example, reaction mixture extractedfrom the primary reaction zone/s could be passed into a first principalreaction zone in which a reduced temperature conversion step is carriedout. The obtained chlorinated alkane rich product could then be passedinto a second principal reaction zone downstream of the first principalreaction zone in which a heat treatment or UV exposure step isperformed, to convert the bulk of the remaining unreacted chlorinatedalkene present to the chlorinated alkane product. Alternatively, thereduced-temperature conversion step and heating and/or UV exposure stepscould all take place in the principal reaction zone.

Thus, in embodiments of the invention, a plurality of principal reactionzones may be employed in sequence. For ease of comprehension, these maybe characterised as upstream principal reaction zones and downstreamprincipal reaction zones, the upstream principal reaction zones beingupstream of the downstream principal reaction zones when those zones areoperated in sequence.

In such embodiments, there may be any number of upstream principalreaction zones and/or downstream principal reaction zones, for example1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 or more upstream principal reactionzones and/or downstream principal reaction zones.

Where such arrangements are employed, heat treatment and/or light (e.g.ultraviolet light) exposure may be conducted in some or all of theupstream and/or downstream principal reaction zones. The intensity ofthe light exposure may be higher in the downstream principal reactionzones. Additionally or alternatively, the wavelength of the light towhich the reaction mixture is exposed in the downstream principalreaction zones may be lower than that in the upstream principal reactionzones.

In certain embodiments of the invention, heat treatment and/or lightexposure steps may only be conducted in the downstream principalreaction zones.

One advantage of the processes of the present invention is that desirousresults are obtained whether the primary and/or principal reaction zonesare operated in a continuous or batch process. The terms ‘continuousprocess’ and ‘batch process’ will be understood by those skilled in theart.

Any type of reactor known to those skilled in the art may be employed inthe processes of the present invention. Specific examples of reactorsthat may be used to provide primary reaction zone/s and/or principalreaction zone/s are column reactors (e.g. column gas-liquid reactors),tubular reactors (e.g. tubular gas phase reactors), bubble columnreactions, plug/flow reactors and stirred tank reactors, for examplecontinuously stirred tank reactors.

Reactors used in the present invention may be divided into differentzones each having different flow patterns and/or different operatingtemperatures/pressures. For example, the principal conversion step maybe performed in a reactor including a plurality of principal reactionzones. Those zones may be operated at different temperatures and/orpressures. For example, in embodiments where the principal conversionstep is a reduced temperature conversion step, the principal reactionzones may be operated at successively lower temperatures.

Additionally or alternatively, reactors used in the processes of thepresent invention may be provided with external circulation loops. Theexternal circulation loops may optionally be provided with coolingand/or heating means.

As those skilled in the art will recognise, reaction zones can bemaintained at differing temperatures through use of cooling/heatingelements such as cooling tubes, cooling jackets, cooling spirals, heatexchangers, heating fans, heating jackets or the like.

Some or all of the primary and/or principal reaction zones used in theprocesses of the present invention may be exposed to visible light(natural or artificially generated), ultra violet light and/or beoperated in darkness.

Chlorine, either in liquid, in solution, and/or gaseous form, may be fedinto the principal reaction zone/s. Chlorinated alkene may also oralternatively be fed into the principal reaction zone/s, if required.

Those skilled in art will recognise that, in certain embodiments, thereaction zones utilised at any stage in the processes of the presentinvention may require agitation means, e.g. stirrers, followers, flowchanneling means or the like and the use of such means in the primaryand/or principal reaction zones in the processes of the presentinvention is envisaged. The primary and/or principal reaction zones maybe operated with differing flow types of reaction mixture.

The primary and/or principal reaction zones employed in the processes ofthe present invention may be located within a single or multiplereactors. Thus, for example, in embodiments of the invention, all of theprimary reaction zones could be different reaction zones in a singlereactor, for example, a column liquid-gas reactor.

Alternatively, the primary reaction zones could be in different reactors(e.g. a series of continuously stirred tank reactors) or even differenttypes of reactors (e.g. one or more primary reaction zones could be in acontinuously stirred tank reactor and additional primary reaction zone/scould be in a tube reactor).

It has unexpectedly been found that the formation of chlorinated alkanedegradation products can be minimised if the apparatus employed tooperate the processes of the present invention (or at least those partsof it which come into contact with the reaction mixture and/or productstreams) does not comprise certain materials.

Thus according to a further aspect of the present invention, there isprovided a process for producing a highly pure chlorinated alkane from achlorinated alkene starting material wherein the apparatus forconducting the process is configured such that those parts of theapparatus which come into contact with the chlorinated alkane productand/or the chlorinated alkene, in use of the apparatus, comprise lessthan about 20%, about 10%, about 5%, about 2% or about 1% of iron.

In such embodiments of the present invention, the apparatus forconducting the process is configured such that those parts of theapparatus which come into contact with the chlorinated alkane productand/or the chlorinated alkene are produced from fluoropolymers,fluorochloropolymers, glass, enamel, phenolic resin impregnatedgraphite, silicium carbide and/or fluoropolymer impregnated graphite.The combination of glass, PVDF, ETFE and Hastelloy, may be used forachieving a combination of effects, for example to provide the necessaryconditions for visible or ultraviolet light to be provided to thereaction mixture while also ensuring that other problems such ascorrosion and temperature are controlled.

In embodiments of the invention, the principal reaction zone is in aplug/flow reactor. An advantage of the use of such apparatus is that thereactor can be configured to minimise or prevent back flow mixing.

The process steps outlined above minimise the formation of impurities,especially those impurities which are difficult to remove from thetarget chlorinated alkane product.

To maximise the purity of the reaction mixture extracted from theprimary reaction zone or the chlorinated alkane rich product obtainedfrom the principal reaction zone, additional purification steps may becarried out. For example, one or more distillation steps may beconducted. Such distillation steps may be conducted under lowtemperature/reduced pressure conditions.

Additionally or alternatively, one or more hydrolysis steps may beperformed. In embodiments in which the reaction mixture/chlorinatedalkane rich product (either typically being a mixture comprising thechlorinated alkene, the chlorinated alkane and impurities includingoxygenated organic compounds) is subjected to a hydrolysis step, thistypically involves contacting the reaction mixture extracted from theprimary reaction zone/chlorinated alkane rich product with an aqueousmedium in a hydrolysis zone. Examples of aqueous media which may beemployed in the hydrolysis step include water, steam and aqueous acid.

Hydrolysis is conducted at appropriate conditions to allow hydrolysisreaction(s), if any, to proceed.

Performance of a hydrolysis step is preferable as this reduces thecontent of oxygenated organic compounds present in the reactionmixture/chlorinated alkane rich product.

Examples of oxygenated organic compounds include chlorinated alkanols,chlorinated acid chlorides, chlorinated acids, or chlorinated ketones.

In embodiments of the invention in which a hydrolysis step is performed,the reaction mixture/chlorinated alkane rich product subjected to such astep may have an oxygenated organic compound content of about 500 ppm orless, about 200 ppm or less, about 100 ppm or less, about 50 ppm orless, or about 10 ppm or less.

Thus, according to a further aspect of the present invention, there isprovided a process for removing oxygenated organic compounds from achlorinated alkane rich product (obtainable from any upstream process)comprising a chlorinated alkane, a chlorinated alkene and oxygenatedorganic compounds, comprising feeding the chlorinated alkane richproduct into an aqueous treatment zone, contacting the chlorinatedalkane rich product with an aqueous medium to produce a mixture andextracting i) an organic phase from that mixture or ii) a chlorinatedalkane stream from that mixture, the organic phase/chlorinated alkanestream comprising reduced levels of oxygenated organic compounds ascompared to the chlorinated alkane rich product fed into the aqueoustreatment zone.

In processes of the present invention in which a hydrolysis step isperformed, the reaction mixture/chlorinated alkane rich product fed intothe aqueous treatment zone may have a low chlorine content, for exampleabout 0.8% or less, about 0.5% or less, about 0.1% or less, about 0.05%or less or about 0.01% or less. For the avoidance of doubt, wherereference is made in this context to chlorine, this encompasses freechlorine, unreacted chlorine, and dissolved chlorine. Chlorine which isbonded to atoms other than chlorine should not be considered.

In embodiments of the invention, the hydrolysis zone is in a washingtank. In such embodiments, the reaction mixture/chlorinated alkane richproduct may be washed with water and/or steam.

Once the reaction mixture/chlorinated alkane rich product has beencontacted with the aqueous medium to form a mixture in the hydrolysiszone, that mixture may be subjected to one or more treatment steps. Forexample, components of reaction mixture/chlorinated alkane rich product(e.g. the chlorinated alkane product and/or unreacted chlorinated alkenestarting material) can be extracted from the mixture formed in theaqueous treatment zone, for example via distillation preferably underreduced pressure and/or low temperature. Such a step can be achievedwhile the mixture is present in the aqueous treatment zone. Additionallyor alternatively, the mixture may firstly be extracted from the aqueoustreatment zone and subjected to the extraction step remotely from thatzone.

Additionally or alternatively, in embodiments of the invention, abiphasic mixture may be formed in the aqueous treatment zone. In suchembodiments, a phase separation step may be performed in which theorganic phase comprising at least the chlorinated alkane component ofthe reaction mixture/chlorinated alkane rich product is separated fromthe aqueous waste phase. This may be achieved by the sequentialextraction of the phases from the aqueous treatment zone. Alternatively,the biphasic mixture could be extracted from the aqueous treatment zoneand subjected to a phase separation step remote from the aqueoustreatment zone to extract the organic phase.

The organic phase may, after optional filtering may then be subjected todistillation to obtain streams comprising purified chlorinated alkaneproduct and/or unreacted chlorinated alkene starting material. Thechlorinated alkene starting material may be recycled to the primaryand/or principal reaction zone/s.

Additionally or alternatively, the organic phase can be subjected toadditional hydrolysis steps as outlined above. The hydrolysis steps canbe repeated if required, for example, one, two, three or more times.

In embodiments of the invention, mixtures comprising the chlorinatedalkane of interest (e.g. the reaction mixture obtained from the primaryreaction zone, the chlorinated alkane rich product obtained from theprincipal reaction zone, the mixture formed in the aqueous treatmentzone and/or the organic phase extracted from the biphasic mixture) canbe subjected to a distillation step, preferably conducted at atemperature of about 100° C. or lower, about 90° C. or lower or about80° C. or lower.

Such a distillation step may be conducted under vacuum. Where vacuumdistillation is carried out, the vacuum conditions may be selected suchthat the distillation may be conducted at a low temperature and/or tofacilitate the extraction of higher molecular weight chlorinatedalkanes.

In embodiments of the invention, any distillation steps conducted in theprocess of the present invention may result in streams comprising atleast about 50%, at least about 80%, at least about 90%, at least about95%, at least about 97%, at least about 98%, at least about 99%, atleast about 99.5%, at least about 99.7%, at least about 99.8%, or atleast about 99.9% of i) unreacted chlorinated alkene starting materialand/or ii) chlorinated alkane product being obtained. As used herein,the term ‘streams’ should be construed broadly to encompass acomposition obtained from any distillation step, regardless of theapparatus used or the form of the composition obtained.

Any distillation equipment known to those skilled in the art can beemployed in the processes of the present invention, for example adistillation boiler/column arrangement. However, it has unexpectedlybeen found that the formation of chlorinated alkane degradation productscan be minimised if distillation apparatus formed of certain materialsare avoided.

Thus according to a further aspect of the present invention, there isprovided a method of distilling a chlorinated alkane rich product(regardless of the process from which it was obtained), in whichdistillation apparatus is employed, the distillation apparatus beingfree of components which, in use of the distillation apparatus, wouldcome into contact with the process fluids (including the liquid ordistillate) and comprise about 20% or more, about 10% or more, about 5%or more, about 2% or more or about 1% or more of iron.

In embodiments of the invention in which distillation step/s are carriedout, the distillation apparatus may be configured such that all of itscomponents which, in use of the distillation apparatus, would come intocontact with the distillate or process fluid, are produced fromfluoropolymers, fluorochloropolymers, glass, enamel, phenolic resinimpregnated graphite, silicium carbide and/or fluoropolymer impregnatedgraphite.

Where distillation steps are performed as part of the processes of thepresent invention, streams obtained in such steps which comprise thechlorinated alkene starting material employed in the processes of theinvention may be recycled and fed into the primary and/or principalreaction zone/s.

The processes of the present invention are particularly advantageous asthey enable highly pure chlorinated alkanes to be produced using simpleand straightforward techniques and equipment with which one skilled inthe art would be familiar.

As can be seen from the disclosure provided herein, the inventiveprocesses of the present invention can be operated in an integratedprocess in a fully continuous mode, optionally in combination with otherprocesses. The process steps of the present invention may employstarting compounds which are converted to highly pure intermediateswhich are themselves further processed to the required targetchlorinated compounds. Those compounds have the requisite purity to beemployed as feedstocks in a range of downstream processes, for examplehydrofluorination conversions.

In embodiments of the invention, the processes of the invention can beused to produce high purity chlorinated alkane compositions whichcomprise:

-   -   The chlorinated alkane product in amounts of at least about 95%,        at least about 99.5%, at least about 99.7%, at least about        99.8%, at least about 99.9%, or at least about 99.95%, and one        or more of the following:    -   Oxygenated organic compounds in amounts of less than about 500        ppm, about 250 ppm or less, about 100 ppm or less, about 50 ppm        or less, or about 10 ppm or less,    -   Isomers of the chlorinated alkane of interest in amounts of less        than about 500 ppm or less, about 250 ppm or less, or about 100        ppm or less,    -   Non-isomeric alkane impurities in amounts of less than about 500        ppm, about 250 ppm or less, or about 100 ppm or less,    -   Chlorinated alkenes in amounts of less than about 500 ppm, about        250 ppm or less, about 100 ppm or less, or about 50 ppm or less,    -   Water in amounts of less than about 500 ppm, about 250 ppm or        less, about 100 ppm or less, or about 50 ppm or less,    -   Inorganic compounds of chlorine in amounts of about 100 ppm or        less, about 50 ppm or less, about 20 ppm or less, or about 10        ppm or less,    -   Brominated organic compounds in amounts of about 100 ppm or        less, about 50 ppm or less, about 20 ppm or less, or about 10        ppm or less, and/or    -   Iron, in amounts of less than about 500 ppm, less than about 200        ppm, less than about 100 ppm, less than about 50 ppm, less than        about 20 ppm, less than about 10 ppm or less than about 5 ppm.

For the avoidance of doubt, the term ‘inorganic compounds of chlorine’encompasses non-organic compounds containing chlorine, includingchlorine (Cl₂), hydrogen chloride and phosgene.

In embodiments of the present invention, the composition may compriseless than about 1000 ppm, less than about 500 ppm, less than about 200ppm, or less than about 100 ppm of organic compounds other than thechlorinated alkane of interest. Additionally or alternatively, thecomposition may collectively comprise less than about 0.5%, less thanabout 0.3%, less than about 0.1% of organic compounds other than thechlorinated alkane of interest.

In embodiments in which the chlorinated alkane product is1,1,1,2,3-pentachloropropane, the process of the invention can be usedto produce a high purity composition which comprises:

-   -   1,1,1,2,3-pentachloropropane in amounts of at least about 99.6%,        at least about 99.7%, at least about 99.8%, at least about        99.9%, or at least about 99.95%,    -   Oxygenated organic compounds, including chlorinated propionyl        chloride, chlorinated propanol and chlorinated propionic acid in        amounts of about 1000 ppm or less, about 500 ppm or less, about        100 ppm or less, about 50 ppm or less, or about 10 ppm or less        of all three compounds,    -   Chlorinated propane isomers other than        1,1,1,2,3-pentachloropropane in amounts of 1000 ppm or less,        about 500 ppm or less, about 250 ppm or less, or about 100 ppm        or less,    -   Chlorinated propenes in amounts of 1000 ppm or less, about 500        ppm or less, about 250 ppm or less, about 100 ppm or less, or        about 50 ppm or less,    -   Water in amounts of about 500 ppm or less, about 250 ppm or        less, or about 100 ppm or less,    -   Brominated organic compounds in amounts of about 100 ppm or        less, about 50 ppm or less, about 20 ppm or less, or about 10        ppm or less    -   Inorganic compounds of chlorine in amounts of about 100 ppm or        less, about 50 ppm or less, about 20 ppm or less or about 10 ppm        or less and/or    -   Iron in amounts of about 100 ppm or less, about 50 ppm or less,        about 20 ppm or less, about 10 ppm or less or about 5 ppm or        less.

In embodiments of the present invention in which the chlorinated alkaneproduct is 1,1,1,2,3-pentachloropropane, the composition may compriseless than about 1000 ppm, less than about 500 ppm, less than about 200ppm, or less than about 100 ppm of organic compounds other than1,1,1,2,3-pentachloropropane. Additionally or alternatively, thecomposition may comprise less than about 1000 ppm, less than about 500ppm, less than about 200 ppm, or less than about 100 ppm of1,1,3,3-Tetrachloropropene, 1,1,1,2,3,3-Hexachloropropane, and/or1,1,1,2.2.3-Hexachloropropane.

As mentioned previously, the prior art fails to disclose or teachprocesses for producing chlorinated alkanes having such a high degree ofpurity and in high yield, with selective reaction. Thus, according tofurther aspects of the present invention, there are provided high puritychlorinated alkane compositions as set out above.

Additionally, the compositions as outlined above have impurity profileswhich make them especially well suited to use as starting materials inthe synthesis of fluoroalkanes or fluoroalkenes and/or chlorofluorinatedalkenes. Thus, according to a further aspect of the present invention,there is provided the use of the compositions outlined herein asfeedstocks in the synthesis of the above-identifiedfluoroalkanes/fluoroalkenes and/or chlorofluoroalkenes. In oneembodiment of this aspect of the present invention, the compositions maybe used to produce 2,3,3,3-tetrafluoropropene (HFO-1234yf)). In anotherembodiment of this aspect of the present invention, the compositions maybe used to produce 2-chloro-3,3,3-trifluoropropene (HFO-1233xf).

The reaction zones employed at any stage in the processes of the presentinvention may be operated at differing pressures and/or temperaturesand/or have differing flows (e.g. flows of differingintensity/direction) of reaction mixture therein.

The reaction zones employed at any stage in the processes of the presentinvention may be operated in sequence (e.g. where reaction mixture ispassed from an initial upstream reaction zone to a terminal downstreamreaction zone, optionally via intermediate reaction zones) and/or inparallel.

In embodiments where the reaction zones are operated in sequence and atdiffering temperatures and/or pressures, the temperature and/or pressurein some or all of the reaction zones may increase or decreasesuccessively.

One, some or all of the reaction zones employed in the processes of thepresent invention may be operated at subatmospheric, atmospheric orsuperatmospheric pressure.

For the avoidance of doubt, where reference is made to units of pressure(kPa) it is the absolute value which is identified. Where values arepresented as percentages, they are percentages by weight unlessotherwise stated.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1—Primary conversion and principal conversion steps(1,1,3-trichloropropene conversion to 1,1,1,2,3-pentachloropropane)

1 gaseous chlorine 2 column gas-liquid reactor 3 external circulationloop 4 external cooler 5 external circulation loop 61,1,3-trichloropropene feed stream 7 external circulation loop 81,1,1,2,3-pentachloropropane-rich stream 9 cooler 101,1,1,2,3-pentachloropropane-rich stream (feed to hydrolysis step, FIG.2) 11 off-gas

FIG. 2—Hydrolysis step

101 water stream 102 1,1,1,2,3-pentachloropropane-rich feed stream 103washing tank 104 washing tank outlet 105 filter 106 filter cake 1071,1,1,2,3-pentachloropropane-rich product stream 108 wastewater stream

FIG. 3—Distillation step

201 1,1,1,2,3-pentachloropropane-rich feed stream (product stream 107,FIG. 2) 202 distillation boiler 203 distillation residue stream 204filter 205 filter cake 206 heavies stream 207 vacuum distillation column208 distillate stream 209 condenser 210 intermediate line 211 liquiddivider 212 reflux stream 213.1 1,1,3-trichloropropene stream 213.21,1,1,3-tetrachloropropane stream 213.3 purified1,1,1,2,3-pentachloropropane stream

EXAMPLES

Abbreviations Used:

TCPe=1,1,3-trichloropropenePCPa=1,1,1,2,3-pentachloropropaneHCE=hexachloroethaneDCPC=dichloropropanoylchloride

The present invention is now further illustrated in the followingexample.

Example 1—Continuous Production of 1,1,1,2,3-Pentachloropropane

A schematic diagram of the equipment used to perform the primaryconversion step and principal conversion step of the present inventionis provided as FIG. 1. A liquid stream of 1,1,3-trichloropropene is fedvia line 6 into an external circulation loop 3, 5, 7 connected to acolumn gas-liquid reactor 2. Gaseous chlorine is fed in the reactor 2via line 1. The reactor 2 is includes a single primary reaction zone,namely circulation loop 3, 5, 7 and lower part of the reactor 2. Thecirculation loop 3, 5, 7 is provided with an external cooler 4 tocontrol the temperature of the reaction mixture. Thorough mixing of1,1,3-trichloropropene and chlorine is achieved within the primaryreaction zone. The primary conversion step could equally be conducted inone or more other types of reactor, such as continuously stirred tankreactor/s.

The operating temperature within the primary reaction zone is 0° C. to20° C. Operating the reactor within this range was found to minimise theformation of pentachloropropane isomers, which are difficult to separatefrom the target product, 1,1,1,2,3-pentachloropropane. Thorough mixingof the reaction mixture and mild temperatures, but also controlling theproportion of 1,1,1,2,3-pentachloropropane present in the reactionmixture, was found to minimise serial reactions of1,1,3-trichloropropene and the formation of 1,1,1,3,3-pentachloropropane(which is difficult to separate from 1,1,1,2,3-pentachloropropane). Toincrease the rate of reaction at the low temperatures, the reactionmixture is exposed to visible light.

The reaction mixture is then passed up through the reactor 2 for theprincipal conversion step, which is performed as a reduced temperatureconversion step. Cooling of the reaction mixture is achieved usingcooling tubes, and the reaction mixture is passed through a series ofupstream and downstream principal reaction zones (not shown), resultingin zonal chlorination of 1,1,3-trichloropropene. To drive the reactiontowards completion, the reaction mixture in the downstream principalreaction zone is exposed to ultraviolet light. Advantageously, thisfully utilizes the chlorine starting material such that the obtainedreaction mixture which is extracted from the downstream-most principalreaction zone has very low levels of dissolved chlorine.

Operating the principal reaction zones at such temperatures has beenfound to minimise the serial reactions of 1,1,3-trichloropropene, whichresult in the formation of unwanted and problematic impurities, such ashexachloropropane.

A 1,1,1,2,3-pentachloropropane rich stream is extracted from reactor 2via line 8. Off-gas is extracted from the reactor 2 via line 11. The1,1,1,2,3-pentachloropropane rich stream is subjected to cooling using aproduct cooler 9 and passed via line 10 for a hydrolysis step. Aschematic diagram illustrating the equipment used to conduct this stepis presented as FIG. 2.

In that equipment, the 1,1,1,2,3-pentachloropropane rich stream is fedinto washing tank 103 via line 102. Water is fed into the washing tankvia line 101 to form a biphasic mixture. The organic phase (containingthe 1,1,1,2,3-pentachloropropane rich product) can easily be separatedfrom the aqueous phase by the sequential removal of those phases vialine 104. The extracted phases are filtered 105 with the filter cakebeing removed 106. The 1,1,1,2,3-pentachloropropane rich product is thenfed via line 107 for further processing while wastewater is removed vialine 108.

The hydrolysis step is especially effective at removing oxygenatedorganic compounds, such as chlorinated propionyl chloride and theircorresponding acids and alcohols, which may be formed during theprocesses of the present invention. While the formation of suchcompounds can be avoided by excluding the presence of oxygen from theupstream stages of the synthesis, doing so increases the cost ofproduction. Thus, the hydrolysis step assists with the economic andstraightforward removal of such otherwise problematic (owing to thedifficulty of removing them, e.g. by distillation) impurities.

To maximise the purity of the obtained 1,1,1,2,3-pentachloropropane, avacuum distillation step was performed, using the apparatus shown inFIG. 3, namely a distillation boiler 202 and vacuum distillation column207. Advantageously, the components of the distillation apparatus whichcome into contact with the process liquid and distillate are formed ofnon-metallic materials which prevents the formation of degradationproducts of the 1,1,1,2,3-pentachloropropane.

The vacuum distillation column 207 is provided with a liquid side streamwithdrawal which can be used to prevent contamination of the productstream with light molecular weight compounds which may be formed in theboiler.

The 1,1,1,2,3-pentachloropropane rich product from the apparatus shownin FIG. 2 is fed into boiler 202 via line 201. A residue is extractedfrom the distillation boiler 202 via line 203, subjected to filteringusing a filter 204. The filter cake is extracted from the system 205 anda heavies stream is extracted via line 206 and subjected to furtherprocessing.

Distillate is taken from the distillation column 201 via line 208, fedvia condenser 209, intermediate line 210 and liquid divider 211 to yielda streams of i) 1,1,3-trichloropropene via line 213.1 which is recycledto the primary reaction zone, ii) 1,1,1,3-tetrachloropropane via line213.2 and purified 1,1,1,2,3-pentachloropropane via line 213.3. A refluxstream 212 from divider 211 is fed back into the vacuum distillationcolumn 207.

Using the apparatus and process conditions outlined above, 3062 kg of1,1,3-Trichloropropene (113TCPe, purity 97.577%) was continuouslyprocessed with an average hourly loading 44.9 kg/h to produce1,1,1,2,3-Pentachloropropane (11123PCPa). Basic parameters of theprocess are as follows:

Basic parameters Reactor overall mean residence time (min) 375 Reactortemperature range (° C.) 1-30 Reactor pressure (kPa) 101 Overallreaction 113TCPe conversion (%) 91.3 Overall 11123PCPa reaction yield(mol PCPa/mol TCPe 97.9 converted, in %) Overall 11123PCPa yieldincluding the all process steps 97.4 described in Example 1

The full impurity profile of the purified product obtained in line213.3. in FIG. 3 of the above-described embodiment is presented in thefollowing table:

Compound (% wt) Phosgene ND 1,1,3-Trichloroprop-1-ene 0.0072,3-Dichloropropanoylchloride ND 1,2.3-Trichloropropane ND2,3,3,3-Tetrachloroprop-1-ene 0.001 1,1,3,3-Tetrachloroprop-1-ene 0.0031,1,1,3-Tetrachloropropane 0.002 1,1,2,3-Tetrachloroprop-1-ene 0.0031,1,3,3,3-Pentachloroprop-1-ene 0.001 1,1,1,3,3-Pentachloropropane 0.004hexachloroethane ND 2,3-Dichloropropanoicacid ND1,1,1,2,3-Pentachloropropane 99.967  1,1,2,2,3-Pentachloropropane 0.0011,1,1,3-Tetrachlororopropane-2-ol 0.0011-Bromo-1,1,2,3-Tetrachloropropane ND 2-Bromo-1,1,1,3-TetrachloropropaneND 1,1,1,3,3,3-Hexhachloropropane ND 1,1,1,2,3,3-Hexachloropropane 0.0021,1,1,2,2,3-Hexachloropropane 0.001 1,2-Dibromo-1,1,3-TrichloropropaneND HCl as Cl— ND H₂O 0.005 ND means below 0.001% wt.

Example 2—Ultra Pure Composition 1,1,1,2,3-Pentachloropropane (PCPA)

The process of Example 1 was repeated four times and samples of1,1,1,2,3-pentachloropropane were obtained following distillation usingthe apparatus illustrated in FIG. 3. Distillation was conducted at apressure of around 15 mBar and at a maximum boiler temperature of 105°C. As can be seen in the following table, the process of the presentinvention enables highly pure PCPA, including very low levels ofimpurities, particularly 1,1,2,2,3-pentachloropropane which is verydifficult to separate from 1,1,1,2,3-pentachloropropane usingdistillation. Note that the figures in this table are provided aspercentages by weight of the composition.

Trial Number Compound 2-1 2-2 2-3 2-4 Phosgene ND ND ND ND1,1,3-Trichloroprop-1-ene 0.0014 0.0012 0.0006 0.00142,3-Dichloropropanoyl chloride ND ND ND ND 1,2.3-Trichloropropane ND NDND ND 2,3,3,3-Tetrachloroprop-1-ene 0.0005 0.0002 <0.0001  0.00021,1,3,3-Tetrachloroprop-1-ene 0.0017 0.0021 0.0008 0.00151,1,1,3-Tetrachloropropane 0.0023 0.0013 0.0007 0.00131,1,2,3-Tetrachloroprop-1-ene 0.0018 0.0021 0.0008 0.00111,1,3,3,3-Pentachloroprop-1-ene ND ND ND ND 1,1,1,3,3-Pentachloropropane0.002  0.0022 0.0009 0.0016 hexachloroethane ND ND ND <0.0001 2,3-Dichloropropanoic acid ND ND ND ND 1,1,1,2,3-Pentachloropropane99.984  99.985  99.993  99.989  1,1,2,2,3-Pentachloropropane 0.00060.0009 0.0008 0.0009 1,1,1,3-Tetrachlororopropane-2-ol 0.001  0.00080.0006 0.0005 1-Bromo-1,1,2,3-Tetrachloropropane ND ND ND ND2-Bromo-1,1,1,3-Tetrachloropropane ND ND ND ND1,1,1,3,3,3-Hexachloropropane ND ND ND ND 1,1,1,2,3,3-Hexachloropropane0.0006 0.0004 ND 0.0005 1,1,1,2,2,3-Hexachloropropane ND 0.0003 ND ND1,2-Dibromo-1,1,3-Trichloropropane ND ND ND ND Moisture (mg/kg) 44    23     NP NP Iron (mg/kg) <0.05   0.05  NP NP HCl as Chlorides (mg/kg)0.51  0.53  NP NP ND = below 1 ppm, NP = not performed

Example 3—Effect of Water Treatment

Crude 1,1,1,2,3-Pentachloropropane compositions were obtained using theapparatus depicted in FIG. 1 and described in Example 1 above, e.g. thecompositions were obtained from line 10 in FIG. 1. One stream (Trial3-1) was not subjected to a hydrolysis step, while the other was (Trial3-2), using the apparatus shown in FIG. 2 and described in Example 1above. The resulting crude compositions were then subjected todistillation. The purity of and oxygenated compound contents of thesamples, pre- and post-distillation, are shown in the following table:

Trial Number 3-1 3-2 Pre-distillation 1,1,1,2,3-Pentachloropropane89.038 91.402 Sum of oxygenated as 0.006 0.001 propanoyl chlorides andtheir acids Post-distillation 1,1,1,2,3-Pentachloropropane 99.948 99.930Sum of oxygenated as 0.006 <0.001 propanoyl chlorides and their acids

As is apparent, the washing step can be successfully employed tominimise the content of oxygenated organic impurities in compositionsrich in chlorinated alkanes of interest.

Example 4—Influence of Molar Ratio of Chlorinated Alkene:ChlorinatedAlkane on Impurity Formation

A batch operated reactor consisting of a four neck glass flask equippedwith a stirrer, thermometer, back cooler, feed and discharge neck andcooling bath was set up. The feedstock consisted of1,1,3-Trichloropropene comprising perchloroethylene and oxygenatedimpurities in amounts observed in commercially sourced supplies.

Minor amounts of HCl gas were formed and these together with traces ofchlorine were cooled down by means of a back cooler/condenser and thenabsorbed in a caustic soda scrubber. Chlorine was introduced into theliquid reaction mixture via dip pipe in various amounts for a period of90 minutes. The temperature of reaction was maintained at 26 to 31° C.Pressure was atmospheric. The chlorine was totally consumed during thereaction. The reaction mixture was sampled and analyzed by GC and theresults of this analysis are shown in the following table:

Trial No. 4-1 4-2 4-3 4-4 4-5 chlorine dosed 20% 40% 60% 80% 100% (mol %of stoichiometry) TCPe:PCPa 90:10 72:28 53:47 33:67 14:86 ratio inreaction mixture (mol %) HCE (w %) 0.015 0.025 0.040 0.064 0.099 DCPC (w%) 0.089 0.067 0.172 0.228 0.322 Other oxygenated 0.009 0.017 0.0300.058 (w %)

As can be seen, increasing the conversion of the chlorinated alkenestarting material to the chlorinated alkane product of interest resultsin an increase in the formation of impurities in the reaction mixture.These disadvantageous results arise as conversion of the startingmaterial to product approaches total conversion.

Example 5—Influence of Molar Ratio of Chlorinated Alkene:ChlorinatedAlkane on Isomeric Selectivity

This example was carried out in as described in Example 4 above.1,1,3-Trichloropropene (purity 94.6% containing 5% of1,1,1,3-Tetrachloropropane as an impurity) was used as the feedstock. 4trials at different reaction temperature were conducted. The samples ofreaction mixture were taken at 80%, 90%, 95% and 100% of stoichiometricquantity of chlorine dosed (based on 113TCPe in the feedstock) and thenanalyzed by gas chromatography. The results of this analysis are shownin the following table:

Chlorine dosed (mol % of 113TCPe in feedstock) Reaction 80% 90% 95% 100%Trial Nr. temp. 11133PCPA content in reaction mixture in % 5-1  6° C.0.028 0.040 0.053 0.075 5-2 25° C. 0.040 0.055 0.071 0.099 5-3 45° C.0.049 0.064 0.076 0.095 5-4 63° C. 0.056 0.071 0.086 0.112

These results demonstrate that increasing the conversion of thechlorinated alkene starting material to the chlorinated alkane productof interest results in a decrease in the selectivity of the reactiontowards the chlorinated alkane isomer of interest. These disadvantageousresults arise as conversion of the starting material to productapproaches total conversion.

Example 6—Influence of Molar Ratio of Chlorinated Alkene:ChlorinatedAlkane on Impurity Formation

This chlorination step was carried out as described in Example 4 above.1,1,3-Trichloropropene (purity 99.4%) was used as a feedstock.

Chlorine was introduced into the liquid reaction mixture at 120% of thestoichiometric quantity towards feedstock 1,1,3-Trichloropropene for aperiod of 90 minutes and was totally consumed during the reaction. Thereaction temperature was 80° C. and reactor pressure was atmospheric.The samples of reaction mixture were taken by 80%, 95%, 110% and 120% ofstoichiometric quantity of the chlorine dosed was analyzed by gaschromatography. Reaction selectivity is expressed in the table below asa ratio between sum of major impurities (1,1,3,3-Tetrachloropropene,1,1,1,2,3,3-Hexachloropropane, 1,1,1,2.2.3-Hexachloropropane) to theproduct 1,1,1,2,3-Pentachloropropane:

Trial Number 6-1 6-2 6-3 6-4 chlorine dosed (mol % 80 95 110 120 ofstoichiometry) TCPe:PCPa ratio in 22:78 11:89 0.6:99.4 0.2:99.8 reactionmixture (mol %) Sum of byproducts/ 3.51 3.59 4.28 6.34 11123PCPa (%)

These results demonstrate that increasing the conversion of thechlorinated alkene starting material to the chlorinated alkane productof interest results in an increase in the formation of unwantedimpurities. These disadvantageous results arise as conversion of thestarting material to product approaches total conversion. As can beseen, the degree of conversion (and thus the formation of impurities)can advantageously and conveniently be achieved by controlling theamount of chlorine into the reaction zone, such that there is no molarexcess of chlorine:chlorinated alkene starting material.

Example 7—Removal of Oxygenated Impurities by Hydrolysis

To demonstrate the effectiveness of the hydrolysis step of the presentinvention at removing oxygenated compounds from the chlorinated alkaneproduct of interest, samples of crude reaction mixture reaction mixturewere obtained using the apparatus depicted in FIG. 1 and described inExample 1 above, e.g. the composition was obtained from line 10 inFIG. 1. The content of a specific oxygenated compound known to beproblematic in downstream reactions was analysed (Feed). The sample wasthen subjected to a hydrolysis step using the apparatus depicted in FIG.2 and described above in Example 1, and the organic phase, e.g. thecomposition obtained from line 107 in FIG. 2 was analysed (Aftertreatment). The results are shown in the following table:

Content of specific Trial Number oxygenated compound (ppm) 7-1 FeedAfter treatment 2,3-Dichloropropanoyl chloride 937 23

As can be seen from this example there is about 97.5% efficiency in theremoval of this specific oxygenated impurity.

1. A process for producing highly pure chlorinated alkane in which achlorinated alkene is contacted with chlorine in a reaction zone toproduce a reaction mixture containing the chlorinated alkane and thechlorinated alkene, and extracting a portion of the reaction mixturefrom the reaction zone, wherein the molar ratio of chlorinatedalkane:chlorinated alkene in the reaction mixture extracted from thereaction zone does not exceed 95:5.
 2. The process of claim 1, whereinthe chlorinated alkene is 1,1,3-trichloropropene and the chlorinatedalkane is 1,1,1,2,3-pentachloropropane.
 3. The process of claim 1,wherein the process is continuous.
 4. The process of claim 1, whereinthe reaction zone is a primary reaction zone.
 5. The process of claim 4,wherein the molar ratio of chlorinated alkane:chlorinated alkene in thereaction mixture extracted from the primary reaction zone does notexceed 50:50.
 6. The process of claim 4, wherein the operatingtemperature in the primary reaction zone is about −10° C. to about 50°C.
 7. The process of claim 4, wherein the reaction mixture extractedfrom the primary reaction zone is subjected to a principal conversionstep in a principal reaction zone to produce a chlorinated alkane richproduct, which is extracted from the principal reaction zone.
 8. Theprocess of claim 7, wherein the molar ratio of chlorinatedalkane:chlorinated alkene in both i) the reaction mixture extracted fromthe primary reaction zone and ii) the chlorinated alkane rich productextracted from the principal reaction zone does not exceed 95:5.
 9. Theprocess of claim 8, wherein the molar ratio of chlorinatedalkane:chlorinated alkene in the chlorinated alkane rich productextracted from the principal reaction zone is higher than the molarratio of chlorinated alkane:chlorinated alkene in the reaction mixtureextracted from the primary reaction zone.
 10. The process of claim 7,wherein the reaction mixture extracted from the primary reaction zoneand/or the chlorinated alkane rich product extracted from the principalreaction zone has a chlorine level of about 1% or less, about 0.5% orless, about 0.1% or less, about 0.05% or less or about 0.01% or less.11. The process of claim 7, wherein the principal conversion stepcomprises a reduced temperature conversion step in which the reactionmixture extracted from the primary reaction is fed into a principalreaction zone operated at a reduced temperature and the chlorinatedalkane rich product is extracted from the principal reaction zone. 12.The process of claim 11, wherein the reduced temperature is about −30°C. to about 30° C.
 13. A process for producing highly pure chlorinatedalkane comprising a reduced temperature conversion step in which areaction mixture comprising chlorinated alkene and chlorinated alkane isfed into a principal reaction zone operated at a temperature of about−30° C. to about 30° C., about −25° C. to about 10° C., or morepreferably about −20° C. to about −10° C., and extracting a chlorinatedalkane rich product from the principal reaction zone.
 14. The processaccording to claim 1, wherein the primary and/or the principal reactionzone is exposed to visible light and/or ultraviolet light.
 15. Theprocess according to claim 7 wherein a plurality of principal reactionzones are employed in sequence and the reaction mixture in thedownstream principal reaction zones is exposed to ultraviolet lightand/or heating.
 16. The process according to claim 15, wherein thereaction mixture in the downstream-most principal reaction zone isexposed to ultraviolet light and/or heating.
 17. The process accordingto claim 1, wherein the level of chlorine present in the primary and/orprincipal reaction zone/s is controlled such that there is no excess ofchlorine present in the reaction mixture present in the primary and/orprincipal reaction zone/s.
 18. The process according to claim 1, whereinthe reaction mixture/chlorinated alkane rich product is subjected to ahydrolysis step.
 19. The process according to claim 18, wherein thehydrolysis step comprises contacting the reaction mixture/chlorinatedalkane rich product with an aqueous medium in an aqueous treatment zone.20. The process according to claim 19, wherein the aqueous medium formsa mixture with the reaction mixture/chlorinated alkane rich product, theprocess further comprising the step of extracting i) an organic phasefrom the mixture and/or ii) a chlorinated alkane stream from thatmixture.
 21. A process for removing oxygenated organic compounds from achlorinated alkane rich product comprising a chlorinated alkane, achlorinated alkene and oxygenated organic compounds, comprising feedingthe chlorinated alkane rich product into an aqueous treatment zone,contacting the chlorinated alkane rich product with an aqueous medium toproduce a mixture and extracting i) an organic phase from that mixtureor ii) a chlorinated alkane stream from that mixture, the organicphase/chlorinated alkane stream comprising reduced levels of oxygenatedorganic compounds as compared to the chlorinated alkane rich product fedinto the aqueous treatment zone.
 22. The process of claim 20 wherein theorganic phase and/or the chlorinated alkane stream extracted from themixture formed in the aqueous treatment zone comprises oxygenatedorganic compounds in amounts of about 1000 ppm or less, about 500 ppm orless, about 100 ppm or less, about 50 ppm or less, or about 10 ppm orless.
 23. The process of claim 18, wherein the reactionmixture/chlorinated alkane rich product fed into the aqueous treatmentzone comprises less than about 0.1%, less than about 0.05% or less thanabout 0.01% chlorine.
 24. The process of claim 1, wherein the reactionmixture/chlorinated alkane rich product/organic phase extracted from themixture formed in the aqueous treatment zone is subjected to one or moredistillation steps.
 25. The process of claim 24, wherein a distillationstep is performed before and/or after the hydrolysis step.
 26. Theprocess of claim 24, wherein the distillation step is performed in adistillation column including a rectification section and a purifiedstream of the chlorinated alkane is extracted as a liquid phase sideproduct from the rectification section of the distillation column.
 27. Amethod of distilling a chlorinated alkane rich product, in whichdistillation apparatus is employed, the distillation apparatus beingfree of components which, in use of the distillation apparatus, comeinto contact with the process fluid and comprise about 20% or more,about 10% or more, about 5% or more, about 2% or more or about 1% ormore of iron.
 28. The method of claim 27, wherein the distillationapparatus is configured such that all of its components which, in use ofthe distillation apparatus, would come into contact with the distillateor process liquid are produced from fluoropolymers,fluorochloropolymers, glass, enamel, phenolic resin impregnatedgraphite, silicium carbide and/or fluoropolymer impregnated graphite.29. A composition obtainable from the process of claim
 1. 30. Thecomposition of claim 29, comprising: The chlorinated alkane product inamounts of at least about 99.7%, at least about 99.8%, at least about99.9%, or at least about 99.95%, and one or more of the following:Oxygenated organic compounds in amounts of less than about 500 ppm,about 250 ppm or less, about 100 ppm or less, about 50 ppm or less, orabout 10 ppm or less, Isomers of the chlorinated alkane of interest inamounts of less than about 500 ppm or less, about 250 ppm or less, orabout 100 ppm or less, Non-isomeric alkane impurities in amounts of lessthan about 500 ppm, about 250 ppm or less, or about 100 ppm or less,Chlorinated alkenes in amounts of less than about 500 ppm, about 250 ppmor less, about 100 ppm or less, or about 50 ppm or less, Water inamounts of less than about 500 ppm, about 250 ppm or less, about 100 ppmor less or about 50 ppm or less, Inorganic compounds of chlorine inamounts of about 100 ppm or less, about 50 ppm or less, about 20 ppm orless, or about 10 ppm or less, Brominated organic compounds in amountsof about 100 ppm or less, about 50 ppm or less, about 20 ppm or less orabout 10 ppm or less, and/or Iron in amounts of about 100 ppm or less,about 50 ppm or less, about 20 ppm or less, about 10 ppm or less orabout 5 ppm or less
 31. A composition comprising: The chlorinated alkaneproduct in amounts of at least about 99.7%, at least about 99.8%, atleast about 99.9%, or at least about 99.95%, and one or more of thefollowing: Oxygenated organic compounds in amounts of less than about500 ppm, about 250 ppm or less, about 100 ppm or less, about 50 ppm orless, or about 10 ppm or less, Isomers of the chlorinated alkane ofinterest in amounts of less than about 500 ppm or less, about 250 ppm orless, or about 100 ppm or less, Non-isomeric alkane impurities inamounts of less than about 500 ppm, about 250 ppm or less, or about 100ppm or less, Chlorinated alkenes in amounts of less than about 500 ppm,about 250 ppm or less, about 100 ppm or less, or about 50 ppm or less,Water in amounts of less than about 500 ppm, about 250 ppm or less,about 100 ppm or less or about 50 ppm or less, Inorganic compounds ofchlorine in amounts of about 100 ppm or less, about 50 ppm or less,about 20 ppm or less or about 10 ppm or less, Brominated organiccompounds in amounts of about 100 ppm or less, about 50 ppm or less,about 20 ppm or less or about 10 ppm or less, and/or Iron in amounts ofabout 100 ppm or less, about 50 ppm or less, about 20 ppm or less, about10 ppm or less or about 5 ppm or less.
 32. The composition of claim 29,wherein the chlorinated alkane is 1,1,1,2,3-pentachloropropane.
 33. Thecomposition of claim 32, wherein the composition comprises less thanabout 1000 ppm, less than about 500 ppm, less than about 200 ppm, orless than about 100 ppm of organic compounds other than1,1,1,2,3-pentachloropropane.
 34. The composition of claim 32, whereinthe composition comprises less than about 1000 ppm, less than about 500ppm, less than about 200 ppm, or less than about 100 ppm of1,1,3,3-Tetrachloropropene, 1,1,1,2,3,3-Hexachloropropane, and/or1,1,1,2,2,3-Hexachloropropane.
 35. The composition of claim 32, whereinsaid composition is free of stabilising agents.
 36. Use of thecomposition of claim 29 as a feedstock for use in the synthesis of afluorinated alkane or fluorinated alkene or chlorofluorinated alkene.37. The use of claim 36 wherein the fluorinated alkene is2,3,3,3-tetrafluoropropene.
 38. The use of claim 36, wherein thechlorofluorinated alkene is 2-chloro-3,3,3-trifluoropropene.
 39. Use ofthe composition of claim 31 as a feedstock for use in the synthesis of afluorinated alkane or fluorinated alkene or chlorofluorinated alkene.40. The use of claim 39 wherein the fluorinated alkene is2,3,3,3-tetrafluoropropene.
 41. The use of claim 39, wherein thechlorofluorinated alkene is 2-chloro-3,3,3-trifluoropropene.
 42. Thecomposition of claim 31, wherein the chlorinated alkane is1,1,1,2,3-pentachloropropane.
 43. The composition of claim 42, whereinthe composition comprises less than about 1000 ppm, less than about 500ppm, less than about 200 ppm, or less than about 100 ppm of organiccompounds other than 1,1,1,2,3-pentachloropropane.
 44. The compositionof claim 42, wherein the composition comprises less than about 1000 ppm,less than about 500 ppm, less than about 200 ppm, or less than about 100ppm of 1,1,3,3-Tetrachloropropene, 1,1,1,2,3,3-Hexachloropropane, and/or1,1,1,2,2,3-Hexachloropropane.
 45. Use of the composition of claim 32 asa feedstock for use in the synthesis of 1,1,2,3-tetrachloropropane. 46.Use of the composition of claim 42 as a feedstock for use in thesynthesis of 1,1,2,3-tetrachloropropane.
 47. The process of claim 21,wherein the reaction mixture/chlorinated alkane rich product fed intothe aqueous treatment zone comprises less than about 0.1%, less thanabout 0.05% or less than about 0.01% chlorine.
 48. The process of claim47, wherein a distillation step is performed before and/or after thehydrolysis step.
 49. The process of claim 48, wherein the distillationstep is performed in a distillation column including a rectificationsection and a purified stream of the chlorinated alkane is extracted asa liquid phase side product from the rectification section of thedistillation column.